cleaning waterways

[jothina]

hi
i need to clean the waterways in the block as the drain tap is blocked, i have removed the tap and cleared it but the hole in the block is blocked deeper than i can poke.
my question is , is there anything i can put in the rad and run through that might clear this before i start taking this apart to gain access with my prodder

thanks
john

[chrisryder]

use a longer prodder? i had the same thing, too that plug out and no water came out! ended up using a very long thin screwdriver to disempact it! the other option is to remove a core plug (if you look along the spark plug side of the engine block you will see 3 discs that look like part of the engine block. these can be removed by drilling a hole in the middle, and then levering out with a screwdriver. this allow best access to the back of the block, and is the only real way to ensure its perfectly clear. if the drain hole is that blocked, the likelihood is the rest is pretty blocked too!

there is a 4th core plug at the back of the engine, but this is not accessible when the engine is in the car, and it is covered by the backplate of the engine. you should be able to remove the other 3 core plugs with the engine fitted. you can buy new plugs (domed discs) and you just place them over the hole (with LOTS of sealant) with the dome facing outwards and hammer the centre to spread them into the recess.

[bmcecosse]

Don't touch the core plugs until you have tried EVERYTHING else. Use a piece of bent wire (coat hanger?) in the drain hole - and flush the system through with rad flush - or drain cleaner ! Just don't leave it in there too long - but do get it up to full temperature and take the car out for a 'thrash' with plenty of revs - then drain it out while hot (care!) and flush through a couple of times with water - again getting up to full temperature each time.

[taupe]

Ive had some success clearing around the waterways with a steel welding rod. Once the tap is removed you can get to the sludge and scale. Leave a hose running in the radiator filler and once it starts to clear you can work your way around the cylinders to some extent. Removing core plugs as above will allow you to get more out!!

[bmcecosse]

But they are a nightmare to refit securely........

[taupe]

Yes they are!!

If you can find the older type thicker ones they are more likely to grip in the hole.

But as BMC implies best left alone

[chrisryder]

mine havent fallen out 6000 miles later... not even dribbled!

[bmcecosse]

Difficult to get a good 'swing' at them with the engine in the car - was your engine out when you fitted them ?

[chrisryder]

yes actually, the trick was finding something a good shape to push the middle, i think we ended up using a carefully sourced socket

[rayofleamington]

I used a socket extension bar and decent sized hammer to re-load mine.
As long as the plug has a good surface around the edge and the holes are perfectly cleaned, they should seal fine.

And yes I'd recommend to leave core plugs alone unless you really have to

[bmcecosse]

Oh it's straightforward enough if the engine is out - the difficult job is doing them in-situ......

[rayofleamington]

the difficult job is doing them in-situ......

never done any on the bench. At least if the engine is in place it won't slide over the bench when you use the landrover sized hammer

On a modern petrol engine - it's worth to disconnect the knock sensor before taking a big hammer to the block.